docs: def _escape_xref(xref_match):
      """Escape things that need to be escaped if they're in a cross-reference.
      """
      xref = xref_match.group()
      xref = xref.replace('/', '%2F')
      xref = xref.replace('?', '%3F')
      xref = xref.replace('#', '%23')
      return xref